This invention relates in general to apparatus for handling and coiling metallic strands. More specifically, it relates to apparatus for guiding and coiling hot, continuous strands without synchronization between the strand advance and the coiler.
One well established system for coiling metallic strands is simply to wind them on a motor driven drum having a horizontal axis of rotation. Another system, commonly termed a "lazy susan" coiler, wraps a horizontally fed strand about a vertically extending core mounted on a rotatable base driven by a motor. While these arrangements appear to be straightforward, in practice there are several serious disadvantages. First, the rate of rotation of the drum or lazy susan must be synchronized with the rate of advance of the strand. Synchronization, however, requires speed sensing and control devices and is prone to malfunction. Second, for strands of appreciable diameter, a heavy-duty power train is required to accelerate and brake the accumulated tons of strand forming a coil. Third, for the horizontal drum coiler, some arrangement such as a cylindrical cam is required to distribute the strand uniformly along the drum.
An alternative system which avoids some of these difficulties is a laying reel type of coiler where the strand is fed downwardly into an annular space in a basket-like receptacle. Usually, there is also some arrangement for guiding the strand from its vertical orientation to a horizontal loop without reversal of the coiling direction or severe mechanical stress on the strand due to sharp bends. U.S. Pat. Nos. 532,565; 627,722 and 854,809 describe such wire coiling apparatus that form the coil by directing the wire through a rotating guide tube with an entrance end adapted to receive the vertically oriented wire and an output end adjacent the annular coiling space. In the U.S. Pat. No. 854,809, the guide tube is secured on a rotating cone-shaped member. A water spray directed on the coil cools it to reduce surface oxidation of the hot strand.
U.S. Pat. No. 3,204,940 to Morgan describes a more recent coiler of this general type which employs a spiral guide projecting from the upper surface of a rotating cone-shaped member. The guide and cone are positioned under the downwardly fed wire and over the coil collecting volume. Morgan also describes a system for directing a flow of cooling air through the coil.
While these systems avoid the heavy power train of drum and lazy susan coilers, they still require close synchronization between the wire feed rate and the rate of rotation of the guide tube or spiral guide. Also, because the discharge end of the guide tube or spiral has a fixed position relative to the collecting volume, the coil tends to form in a non-uniform manner, particularly for larger diameter strands. Another problem with the Morgan coiler, which has been used for small diameter strands, is that the guide tube wears rapidly and must be replaced periodically.
U.S. Pat. No. 3,750,974 discloses another laying reel coil that uses a cone-shaped member to direct an overhead strand to an annular coil collecting space. In this apparatus, however, the cone is stationary and the laying direction is controlled by fluid forces directed over the surface of the cone laterally against the strand. For strands of any appreciable diameter, however, the fluid flow forces are not sufficiently strong to reliably control the formation of the coil.
Because the metallic strands are typically hot and readily fractured, it is also important to convey them from the production site to the coiler without sharp bends. A common arrangement is to use pulleys or a closely conforming guide tube as shown in the aforementioned U.S. Pat. Nos. 532,565; 627,722 and 3,204,940. While these arrangements guide the strand, they do not cool it except through exposure to ambient room temperature air.
It is therefore a principal object of this invention to provide a coiling system for metallic strands that are continuously advancing from a production apparatus which reliably forms uniform, non-tangled coils without synchronization between the rate of advance of the strand and a coiler.
Another object is to provide a coiling system that forms coils of strands of appreciable diameter without heavy power trains.
A further object is to provide a coiling system for hot strands that cools the strands before they are formed into coils to control surface oxidation of the strand and promote formation of the coil.
A still further object is to provide a coiling system that accepts a wide range of strand sizes and production speeds.
Still another object is to provide a coiling system that minimizes mechanical stress on the strand particularly stress due to a reversal of the coiling direction or the formation of kinks.
Yet another object is to provide a coiling system that simultaneously delivers and coils multiple strands and forms uniform coils which are readily transported and readily uncoiled for further fabrication.
Another object is to provide a coiling system with the foregoing advantages that has a comparatively low cost of manufacture.